Wiper blade for a window washing apparatus

ABSTRACT

A wiper blade is proposed which is a part of windshield wiper systems of motor vehicles and is used for cleaning windshields of motor vehicles. The wiper blade has a multi-link elongated support bow system for a wiper strip resting against the windshield and has at least one upper support bow, on whose at least one end a lower support bow is hinged by means of a hinge bolt disposed transversely to the long extension of the support bow, wherein the upper bow of a U-shaped cross section in the area of the hinged connection extends with its U-shaped legs over a section of the lower bow of a U-shaped cross section in such a way, that the U-shaped legs of the two support bows essentially lie parallel with each other. The hinge bolt fittingly projects through the U-shaped legs in openings which are coaxial in respect to each other and the hinge bolt is provided with means for securing it against axial displacement in its center area located between the U-shaped legs of the lower bow. The securing means are connected in one piece with the hinge bolt made of an elastic material and can be deflected against a spring force at least as far as the surface area of the bolt, wherein the securing means have detent shoulders located between the U-shaped legs of the lower bow and facing away from each other, which cooperate with counter-shoulders of the lower bow facing them. It is assured in this way that the lower bow as well as the upper bow are always smoothly pivotable in respect to the hinge bolt.

BACKGROUND OF THE INVENTION

The invention is based on a known wiper blade (U.S. Pat. No. 4,795,288),wherein the hinge bolt has an elastically compressible spindle-shapedthickening in its center section which allows insertion of the hingebolt into its seated position. The two widened ends of the thickeningare arranged and designed in such a way that they jam in the openings ofthe lower bow and cause the fixed seating between the bolt and the lowerbow. If the allowed unavoidable tolerances of the openings are inunfavorable positions, it can occur that the ends of the thickeningsproject through the lower bow and also hold the upper bow in place, sothat the mobility in the support bow joint is at least hampered.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a wiperblade for a window washing apparatus, which avoids the disadvantages ofthe prior art.

In keeping with these objects and with others which will become apparenthereinafter, one feature of the present invention resides, brieflystated in a wiper blade for windshield wiper systems of motor vehicles,which wiper blade has in accordance with the invention the securingmeans end on clearly defined stop shoulders located between the facingsides of the U-shaped legs of the lower bow. Because of this it isimpossible for the securing means to act on the upper bow. Thus, therequired relative movement between the upper and lower bows is assured.

A particularly advantageous embodiment of the securing means results ifthese are constituted by at least one tab-like wing having the stopshoulders, which is connected with one of its long sides with the hingebolt inside the surface area and essentially extends tangentially inrespect to the hinge bolt over the latter's surface area, if furthermorethe wing has a length which is matched to the distance between thefacing surfaces of the U-shaped legs of the lower bow and if furthermorea recess in the hinge bolt, which extends past the length of the wing,is associated with the wing, into which the free end of the wing can becompletely inserted.

A particularly secure hinged connection between the upper and the lowerbow is achieved if, in respect to its length, two tab-like wings aredisposed on the hinge bolt, wherein one recess in the hinge bolt isassociated with each wing.

The two tab-like wings are suitably disposed in two spaced apart planeswhich are parallel with each other.

Advantages in manufacturing the hinge bolt result if, from the directionof their origin on the hinge bolt, the wings extend toward the sameside.

Further advantageous embodiments and improvements of the invention arerecited in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1, a partial lateral view of a wiper blade placed on a windshieldof a motor vehicles,

FIG. 2, a section through a hinged connection between support bows whichare part of the support bow system of the wiper blade, wherein the hingeis embodied in accordance with a first embodiment,

FIG. 3, a section analogous to FIG. 2 through a differently designedhinged connection,

FIG. 4, an enlarged view of the hinge bolt which is part of the hingedconnection,

FIG. 5, a section along the line V--V through the hinge bolt inaccordance with FIG. 4,

FIG. 6, a top view of the hinge bolt in accordance with FIG. 4,

FIG. 7, a section in accordance with FIG. 5 through a differentlydesigned hinge bolt,

FIG. 8, an enlarged view of a section along the line II--II in FIG. 1through a further embodiment of the hinge, wherein the hinge bolt inaccordance with FIG. 4 is in an intermediate assembly position,

FIG. 9, a partial section through the arrangement in accordance withFIG. 8 along the line IX--IX,

FIG. 10, the hinge in accordance with FIG. 8 with the assembly of thehinge bolt completed, and

FIG. 11, a partial section through the arrangement in accordance withFIG. 10 along the line XI--XI in FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A wiper blade 10, with which a multi-link elongated support bow system12 is associated, is partially shown in FIG. 1. The support bow systemis used for holding a resilient wiper strip 14 which is placed on theouter surface of windshield 16 of a motor vehicle, not shown in detail.The support bow system 12 has a plurality of support bows which arehingedly connected with each other in the manner of balance beams, ofwhich a main bow 18 and an intermediate bow 20 are particularly intendedto be examined here. The further remarks particularly deal with thehinged connection 22 between the bows 18 and 20. The hinged connection22 can of course be realized in connection with all the hingedconnections 23 between the other support bows of the support bow system.As FIG. 1 furthermore shows, the main bow 18 lies above the intermediatebow 20, so that in what follows the main bow 18 is identified as theupper bow and the intermediate bow 20 as the lower bow. It canfurthermore be seen that in respect to the claw bows 25 hinged on it,the intermediate bow 20 is to be considered the upper bow in the senseof the invention, wherein the claw bows connected with it via the hingedconnections 23 constitute lower bows in the sense of the invention. Theclaw bows 25 are themselves used for holding the wiper strip 14 and fordistributing a force, indicated by the arrow 11, for placing the wiperblade 10 against the windshield 16.

The particular design of the hinged connections 22 or 23 will beexplained in more detail by means of FIGS. 4 to 10. The sectionsrepresented in FIGS. 2, 3 and 10 show that the upper bow 18 is embodiedto be U-shaped in the area of the hinged connection 22. This alsoapplies to the lower bow 20. In this case the upper bow 18 has aU-shaped base 24 from which the two U-shaped legs 26 extend. The lowerbow 20 also has a U-shaped base 28, which is followed by the twoU-shaped legs 30. It can also be seen that the upper bow 18 extends overthe lower bow 20 sufficiently far so that the U-shaped legs 26 or 30 ofthe two support bows 18 or 20 essentially lie parallel with each other.Since the two support bows 18 and 20 are made of metal, a plastic liner32 has been disposed to prevent a contact between the metal of the twosupport bows 18 and 20. Openings 34 are provided in the legs 26 of theupper bow 18, which are disposed coaxially in respect to openings 36 inthe U-shaped legs 30 of the lower bow 20 (FIG. 10). The openings 34 inthe legs 26 of the upper bow 18 have a slightly larger diameter than isthe case with the openings 36 in the legs 30 of the lower bow 20.Seating eyes 38 of the plastic liner 32 extending into the openings 34reduce the diameter of the openings 34 to the diameter of the openings36. A hinge bolt 40, penetrating the seating eyes 38 and thus theopenings 34 in the upper bow 18 as well as the openings 36 in the lowerbow 20, provides a hinged connection between the upper bow 18 and thelower bow 20.

In the exemplary embodiment in accordance with FIGS. 2 and 3, arespectively outwardly oriented rail 35 is disposed on the openings 34to increase the seating surface of the hinge bolt 40 in the openings 34of the upper support bow 18.

A first embodiment of the hinge bolt 40 is represented in FIGS. 4 to 6.Its diameter is matched to the diameter of the opening 36 in the lowerbow 20 and to the bore diameter of the seating eyes 38 in such a waythat it is freely rotatable in them. In its center area 42 it has twotab-like wings 44 which essentially have a rectangular shape. The wings44 are connected by one of their long sides with the hinge bolt 40. Theconnecting point between the hinge bolt 40 and the wings 44 is locatedinside the surface area of the hinge bolt 40. The wings 44 essentiallyextend tangentially with the surface area 46 and with their free ends 48they project past the surface area 46 of the bolt 40 (FIG. 5). Thelength 50 of the wings 44, measured in the axial direction of the hingebolt 40, is matched to the distance 52 (FIG. 8) between the facingsurfaces 54 of the U-shaped legs 30 of the lower bow 20 in such a waythat it is slightly less than the distance 52. In the exemplaryembodiment the inner, facing surfaces 54 of the lower bow 20 areconstituted by the front faces of annular collars 56, which were formedwhen cutting the openings 36. FIGS. 4 to 6 furthermore show that arecess 58, disposed in the hinge bolt 40, is associated with each one ofthe two wings 44 and extends past the length 50 of the wings 44. Theshape of the recesses 58 is such that the wings 44 of the hinge bolt 40,which is made of a resilient plastic material, can be deflected in thedirection of the arrows 60 (FIG. 5) sufficiently far so that they canenter completely, i.e. also with the free ends 48, into the recesses 58.As further shown in FIG. 5, the two wings 44 are disposed in two planesextending at a distance from and essentially parallel with each other.The wings 44 extend in opposite directions from each other.

Another arrangement of the tab-like wings is represented in FIG. 7. Asection through a hinge bolt 140 is illustrated there, wherein the wings144, which are at a distance from each other and disposed in planesparallel with each other, extend from their point of origin on the hingebolt 140 in the same direction. This arrangement can have advantages inproduction techniques. The basic design of the wings 144 and theassociation of the recesses 158 has also been made such that theproblem-free insertion of the wings 144 into the recesses 158 in thedirection of the arrows 160 is possible (FIG. 7).

The assembly of the hinged connection will be described in detail bymeans of FIGS. 8 to 11. First, the openings 34 or 36 in the U-shapedlegs 26 or 30 are matched to each other in such a way that the hingebolt 40 can be inserted into the openings 34 or 36 in the direction ofthe arrow 41 (FIG. 8). In the process it is of course necessary toinsert the two wings 44 against a resilient force into the recesses 58in the direction of the arrows 60 (FIG. 5) by means of certain aids,such as is illustrated in FIG. 9. When the hinge bolt 40 has reached itsoperational position shown in FIG. 10, the wings 44, which are now nolonger held, spring back into their initial positions opposite thearrows 60 in FIG. 5, in which their free ends 48 again project past thesurface area 46 of the hinge bolt 40 (FIG. 11). In this position the endsurfaces 66 (FIG. 4), which are facing away and are spaced apart fromeach other, viewed in the direction of the longitudinal axis of thehinge bolt 46, form detent shoulders or securing means against axialdisplacement of the bolt 40, which cooperate in the sense of alimitation of the axial play of the hinge bolt 40 with the front faces54 of the U-shaped legs 30 of the lower bow 20 acting as counter-detentshoulders.

In the embodiments of the hinged connection represented in FIGS. 2 or 3,the plastic liner 32 of the just described exemplary embodiment isconstituted by a coating application, not shown in FIG. 2, which isdisposed on at least one of the facing surfaces of the U-shaped legs 26or 30 of the upper bow 18 or the lower bow 20.

In the exemplary embodiment in accordance with FIG. 3, a separate,plate-shaped component 31 made of plastic and in the form of a disk andhaving a through-bore for the hinge bolt 40, is disposed between the twofacing surfaces of the U-shaped legs 26 or 30 instead of the plasticliner 32. Thus, in both embodiments in accordance with FIGS. 2 and 3, anintermediate layer (coating application or plastic disk 31) made of amaterial capable of easy sliding is disposed in the area of the hingebolt between the facing surfaces of the U-shaped legs 26 or 30.

We claim:
 1. A wiper blade for windshield wiper systems of motorvehicles, the wiper blade comprising a wiper strip; and a multi-linkelongated support bow system for supporting said wiper strip, said bowsystem having at least one upper support bow, at least one lower supportbow and a hinge bolt hingedly connecting said support bows with oneanother, said support bows having transverse U-shaped cross-sectionsprovided in an area of said hinge, said U-shaped cross-section of saidupper bow extending over a part of said U-shaped cross-section of saidlower bow so that legs of said support bows extend essentially parallelto one another and have coaxial openings through which said hinge boltextends, said hinge bolt further having means for securing said hingebolt against an axial displacement in said opening with respect to saidbow system, said securing means being connected with said hinge bolt andcomposed of an elastic material to be deflected against a spring forceat least as far as a surface area of said bolt, said securing meansbeing provided with detent shoulders located between said legs of saidlower bow and facing away from one another, and counter shouldersprovided on said lower bow so that said detent shoulders cooperate withsaid counter shoulders.
 2. The wiper blade as defined in claim 1,wherein said said securing means include at least one wing which has onelong side connected with said hinge bolt inside a surface area of saidhinge bolt, said wing extending tangentially with said hinge bolt pastthe surface area and having a length which corresponds to a distancebetween facing surfaces of said legs of said lower bow, said hinge bolthaving a recess extending past a length of said wing, said wing having afree end insertable in said recess.
 3. The wiper blade as defined inclaim 1, and further comprising an intermediate layer of a slidablematerial located in an area of said hinge bolt between facing surfacesof said legs of said upper bow and said lower bow.
 4. The wiper blade asdefined in claim 3, wherein said intermediate layer is formed as acoating provided on at least one of surfaces of said legs.
 5. The wiperblade as defined in claim 3, wherein said intermediate layer is formedas a plate-shaped separate component which is composed of a plasticmaterial and is provided with a through bore for said hinge bolt.
 6. Thewiper blade as defined in claim 3, wherein said intermediate layer isformed as a liner composed of a plastic material, said liner havingseating eyes projecting into said openings of said outer bow.
 7. Thewiper blade as defined in claim 1, and further comprising outwardlydirected rails provided on said upper bow and increasing a seatingsurface in said openings of said upper bow for said hinge bolt.
 8. Awiper blade for windshield systems of motor vehicles, the wiper bladecomprising a wiper strip; and a multi-link elongated support bow systemfor supporting said wiper strip, said bow system having at least oneupper support bow, at least one lower support bow and a hinge bolthingedly connecting said support bows with one another, said supportbows having transverse-U-shaped cross-sections provided in an area ofsaid hinge, said U-shaped cross-section of said upper bow extending overa part of said U-shaped cross-section of said lower bow so that legs ofsaid support bows extend essentially parallel to one another and havecoaxial openings through which said hinge bolts extends, said hinge boltfurther having means for securing said hinge bolt against an axialdisplacement, said securing means being connected with said hinge boltand composed of an elastic material to be deflected against a springforce at least as far as a surface area of said bolt, said securingmeans being provided with detent shoulders located between said legs ofsaid lower bow and facing away from one another, and counter shouldersprovided on said lower bow so that said detent shoulders cooperate withsaid counter shoulders, said securing means including at least onetab-shaped wing which is provided with said detent shoulders, said winghaving one long side connected with said hinge bolt inside a surfacearea of said hinge bolt, said wing extending tangentially with said boltpast the surface area and having a length which corresponds to adistance between facing surfaces of said legs of said lower bow, saidhinge bolt having a recess extending past a length of said wing, saidwing having a free end insertable in said recess.
 9. The wiper blade asdefined in claim 8, wherein said securing means include two tab-shapedwings located on said hinge bolt, said hinge bolt having recessesassociated with said wings.
 10. The wiper blade as defined in claim 9,wherein said tab-shaped wings are located in planes which are spacedfrom one another and are parallel with each other.
 11. The wiper bladeas defined in claim 10, wherein said tab-shaped wings have points oforigin on said hinge bolt and extend from said points of said origin ina same direction.
 12. A wiper blade for windshield wiper systems ofmotor vehicles, the wiper blade comprising a wiper strip arranged torest against a windshield; and a multi-link elongated support bow systemprovided for said wiper strip, said bow system having at least one upperelongated support bow, at least one elongated lower support bow and ahinge bolt hingedly connecting said support bows with one another, saidhinge bolt defining a pivot axis, said support bows having U-shapedtransverse cross-sections provided in an area of said hinge bolt andsaid U-shaped cross-section of said upper bow extends over a part ofsaid U-shaped cross-section of said lower bow so that legs of saidsupport bows extend essentially parallel to one another and have coaxialopenings through which said hinge bolt extends, said hinge bolt havingmeans for securing said hinge bolt against an axial displacement in saidopening with respect to said bow system, said securing means beingconnected with said hinge bolt and composed of an elastic material to bedeflected against a spring force at least as far as a surface area ofsaid bolt, said securing means being provided with detent shoulderslocated between said legs of said lower bow, said shoulders defining endsurfaces extending substantially perpendicular to said axis and facingaway from one another, and counter shoulders provided on said lower bowso that said detent shoulders cooperate with said counter shoulders,said securing means including at least one tab-shaped wing attachedalong a longitudinal edge thereof to said bolt, said wing being providedwith said detent shoulders.